Volume expansion seems inactive

The screenshots aren't showing because images are reviewed by a moderator before they are published (just in case someone posts something inappropriate). Once a moderator approves them they will then show.

I can't see your screenshots, but what you are looking for is to see a resync with a percentage indicator of progress.

You can alternatively copy and paste the text from the output of

watch /cat/proc/mdstat

rather than post a screenshot.

The code tag option (see the </> button) is very good for posting that kind of output.

Say you are using X-RAID you would have md0 (4GB OS volume), md1 (swap) and md127 (data volume).

If you had say 3 disks installed and added a fourth you should see the 4th disk added to md0, md1 and md127. The md0 and md1 resyncs are very quick, but the md127 one would take a while.

If you replace a disk with a higher capacity disk, not only will md0, md1 and md127 need to be rebuilt, but if you have at least two disks of the higher capacity installed a new layer md126 would be added (note this is just an example md127 could be the new layer showing and md126 the one already present).

Once the resyncs have finished you should no longer see a rebuild status or percentage for any of the RAID arrays. The data volume should then expand provided your additions have met the requirements for expansion for the RAID level you have chosen.

If it doesn't expand you could see if a reboot helps.